Pros: This is the GREATEST! I made myself a home bulb, and its at least 3x brighter than the 48 led's they sell here. I used a the small 1w driver, and epoxy'd it into the base, and the wires really install easy on this base without even soldering! The holes are there and the wires are held in my pressure. I applied thermal grease onto the cree I bought, soldered it on, and VOILA!

Cons: Its hard to solder the wires on the cree because this is such a good heat sink it's pretty hard to get the solder to melt to take the wire. But thats ok!

Other Thoughts: I wish the optics that came with it were not made for one led. It would be nicer just to have a clear optic that spreads more.

Bottomline: I just ordered more, I want to make a lot more for my home since these should last 20000+ hours.

Pros: Easy to mount star.
Perfect heat sink: With thermal glue on the star and thermal grease on all threads, thermal management is excellent. I use two of these for a bike light. With the airflow around the fins I am pretty sure that this heat sink could handle even an ssc p7 or CREE MC-E.
All-round size: all 35mm optics I've tried fit. I use the supplied one and sku.4544. The supplied optics is about 20 degrees.

Cons: Not watertight (but it's supposed to be used as a light bulb, so that is to be expected).
All drilled holes for attaching the base of the bulb were not equally sized.

Other Thoughts: I will get more and actually use them for light bulbs.
If heat sink would mount backwards (with the flat side towards the bulb head) a larger star with e.g. 3 CREE LEDs could be mounted.

Bottomline: Very versatile sku. A very good buy, I will get more.

Pros: Very efficient heatsink. I attached a CREE R2 star with thermal glue and added thermal grease to all threads. With the LED driven at 700mA all of the casing is warm within minutes. The Star itself is still only lukewarm.
Any 35mm optics seems to fit. I used two of these casings for a home made bike light. One of them has the optics supplied - it doesn't fit CREE perfectly but still gives a useful 15-20 degree beam. The other one has a 10 degree optics. Together they give a very nice beam. I also tested another 35mm optics, it fitted fine but I didn't like the beam profile.

Cons: Not watertight. This can be solved with some O-rings and silicone.

Since it is meant as a light bulb not a bike light, attaching it to some kind of mount that goes on the bike takes some working out.
I ordered three - diameter of holes for attaching housing differed between them.

Other Thoughts: If the pill could be screwed in the other way around the flat side could be used to attach a larger PCB than a star with e.g. 3 CREE LEDs. Since a 35mm optics for 3 CREE will most probably fit this would give a simple but good host for at 3 CREE bike light.

Bottomline: Very good and stylish heatsink. With the added airflow of a bike light application it would probably be good enough for 3 CREE, MC-E or even SSC P7 application.

Pros: Great heatsink. I'll be buying more soon.
Nice thick aluminium base that fits my star MCPCBs perfectly. The pre-drilled holes are all in very useful spots for adding a star.
I tested the heat transfer between two parts when they were just screwed together without any thermal grease. I heated the base with a 60W soldering iron in the centre and found the outer fins warmed up almost straight away. Even after a few minutes of running the base was always cool enough to touch. Without the fins, the base was too hot to touch within 30 seconds. So I'm very happy with the heat exchange between the base - fins - air.
The cylinder part of the heatsink is threaded at both ends so you can flip it around either way.
The threads are fine on the one I got.

Cons: Tooling marks were visible on the outer parts of the fins. This doesn't bother me. The rest of the heatsink didn't show any marks.

Other Thoughts: I must mention that I'm just using the heatsink to make my own headtorch. So everything but the heatsink is of no interest to me.
I've been using CPU heatsinks so far, but they have all their fins on one side of a flat sheet (of course). This thing puts all the fins beside the LED so it doesn't stick out from my head so far (reducing wobble while I run).

Bottomline: I can see how these would make neat little LED lights. It would be easy to add a driver in the screw base.
As for me, it's a perfect heatsink that will make a very neat headtorch.